Propylamine is a bright, colourless, highly refracting, very mobile liquid, possessing a peculiar, strongly ammoniacal odour. It mixes with water, heat being generated by the mixture. It boils at 50° C., and has a sp. gr. of ·7134 at 21° C.
Propylamine combines with acids, and forms crystallised salts. The chloride is a very deliquescent salt. The sulphate occurs in crystals, and is also deliquescent. See Trimethylamine.
PROPYL′IC ALCOHOL. C3H7O. Syn. Hydrated oxide of propyl, Trityl alcohol. A liquid boiling at 204·8° Fahr., obtained by repeatedly rectifying the first products of the distillation of the fusel oil of marc brandy. It stands to ethylic alcohol (ordinary alcohol) in the same relation in which the latter stands to methylic alcohol (pyroxylic spirit).
PRO′TEIN. The name given by Mülder to a substance which he regarded as the original matter from which animal albumen, casein, and fibrin, were derived; but which is now considered as a product of the decomposition of those important principles by moderately strong caustic alkali.
Prep. (Liebig.) Albumen, casein, or fibrin is dissolved in moderately strong potassa, the solution heated for some time to 120° Fahr., and acetic acid added; a gelatinous precipitate subsides, which, after being washed and dried, is protein.
Obs. The names binoxide and teroxide of protein have been given by Mülder to products of the long-continued action of boiling water upon fibrin in contact with the air.
PRO′TIDE. A soluble, straw-yellow substance, formed, along with other products, by the action of strong solution of potassa on albumen, fibrin, or casein. See Erythroprotide.
PROTO-. See Nomenclature.
PROVI′′SIONS (Preservation of). See Putrefaction.
PRUNES. [Fr.] The fruit of cultivated varieties of Prunus domestica (Linn.). The dried fruit (French prunes or PLUMS; PRUNUM—B. P., Ph. L., PRUNA—Ph. E. & D.) is cooling and gently laxative, and, as such, is useful in habitual costiveness and fevers.